1. Field of the Invention
The present invention relates to an oil supply apparatus for a hermetic compressor, and more particularly, to an oil supply apparatus for a hermetic compressor that is capable of increasing oil supply quantity and increasing a lubricating performance of oil.
2. Description of the Background Art
Generally, a hermetic compressor is as an apparatus for compressing and supplying a fluid and is mainly applied to a cooling system such as a refrigerator, an air conditioner, or the like.
FIG. 1 illustrates a cross-sectional view of a hermetic compressor according to a related art.
Referring to FIG. 1, a hermetic compressor according to a related art includes a hermetic casing 1 providing a hermetic space inside, a motor 3 installed inside the hermetic casing 1 so as to provide a driving power, a compression unit 30 which carries out a compression of a fluid by the driving power of the motor 3, and a oil supply apparatus 20 for supplying an inside of the hermetic casing 1 with an oil so as to perform lubrication and cooling.
The motor 3 includes a stator 4 wound with a magnetization coil and a rotor 5 made of a permanent magnet, thereby generating a turning force by an electromagnetic reciprocal reaction between the stator 4 and rotor 5.
The compression unit 30 includes a crankshaft 7 connected to the motor 3 to rotate and having an eccentric part at an upper part, a connecting rod 8 for transferring a turning force generated from a rotation of the crankshaft 7, a piston 9 connected to the connecting rod 8 to reciprocate so as to carry out a compression of a fluid, a cylinder 6 having the piston 9 reciprocate inside and providing a compression room for compressing the fluid, and a valve assembly 10 arranged at a front side of the cylinder 6 so as to open/close the compressed fluid.
The oil supply apparatus 20 includes an oil flow path 12 formed inside the crankshaft 7 in a lengthwise direction so as to supply sliding and frictional parts inside the compressor with the oil, a sleeve 11 coupled with a lower part of the crankshaft 7 so as to rotate together with the crankshaft 7, a sucking member 13 arranged so as to maintain a predetermined gap with an inner circumferential face of the sleeve 11 and sucking the oil through the gap when the sleeve 11 rotates so as to supply the oil flow path 12 with the sucked oil, and a support bracket 14 supporting the sucking member 13 while it is inserted in the inner circumference face of the sleeve 11.
The sucking member 13, a lower part of which is supported by the support bracket 14, is arranged so as to maintain a predetermined gap with an outer circumferential face of the sleeve 11, as well as to remain relatively stationary inside the sleeve 11 which rotates together with the crankshaft 7. A spiral oil flow path is formed at an outer circumferential face of the sucking member 13 so as to suck the oil along the spiral oil flow path when the sleeve 11 rotates.
The bracket 14 has a predetermined elasticity. A central part of the bracket 14 is fixed to the lower part of the sucking member 13 so as to support the sucking member 13 so that it does not rotate with the sleeve 11. Both extending parts of the bracket 14 from the central part are fixed to the lower part of the stator 4.
Operation of the above-constructed oil supply apparatus for the hermetic compressor is explained as follows.
First, once the motor 3 rotates, the crankshaft 7 rotates to transfer a dynamic power to the compression unit 30 so as to compress the fluid.
When the crankshaft 7 rotates by the rotation of the motor 3, the sleeve 11 rotates while the sucking member 13 supported by the bracket 14 remains stationary inside the sleeve 11. Hence, the oil is sucked in along the spiral oil flow path at the outer circumferential face of the sucking member 13 by the relative rotation of the sleeve 11 for the sucking member 13.
The oil having sucked in through the sucking member 13 is carried to an upper part through the oil flow path 12 of the crankshaft 7 to sliding and exothermic parts of the hermetic casing 1 so as to carry Out lubrication and heat dissipation.
As discussed above, the sucking member 13 is fixed to the bracket in the above-constructed hermetic compressor according to the related art, the sleeve 11 rotates together with the crankshaft 7. When a vibration occurs in driving the compressor, the sucking member 13 is fixed but the sleeve 11 shakes due to the vibration of the compressor. Hence, it is difficult to maintain a precise gap between the outer circumferential face of the sucking member 13 and the inner face of the sleeve 11, whereby the suction power of the oil is reduced. Thus, the frictional and sliding parts in the compressor fail to be supplied with the oil sufficiently. Hence, abrasion and damage are caused on the frictional and sliding parts so as to degrade performance of the hermetic compressor.
Moreover, in the assembly process, the bracket 14 supports the lower part of the sucking member 13 having been inserted in the sleeve 11, and then both ends of the support bracket 14 are fixed to the stator 5. Therefore, the assembly process becomes more complicated.